Any discussion of the related art throughout the specification should in no way be considered as an admission that such related art is widely known or forms part of common general knowledge in the field.
Conventional printing machines often include a photoreceptor belt driven in a cyclical manner by a motor. The motor is typically controlled by a closed-loop feedback controller, such as a proportional-integral-differential controller. The closed-loop controller strives to achieve a desired belt velocity by incorporating feedback from operation of the machine. As shown by the jagged line in FIG. 4, the actual belt velocity closely approximates, but nonetheless varies from, the desired belt velocity.
In conventional machines having an endless belt, that is, a belt having two ends joined together to form a seam, the seam may cause undesirable errors, for example, a torque disturbance outside the bandwidth of the closed-loop system. For example, the operational frequency of the controller may not be adequate to timely detect and resolve the errors resulting from the seam. Instead the controller is late to correct the actual torque disturbance 420 (FIG. 4) and causes a lagged disturbance 424.
Some printing systems, for example, color printing systems benefit from higher degrees of accuracy due to the overlaying of different colored images over one another. Accordingly, it may be desirable to provide systems and method for reducing torque disturbance in devices having an endless belt, for example, printing systems.